1. Field of the Invention
The present invention relates to an object detection apparatus and an object detection method for detecting an object.
2. Description of the Related Art
For a moving vehicle such as a robot, in order to ensure safe movement, it is important to detect an ambient object (obstacle) and to perform an avoidance maneuver corresponding to whether the detected object is a moving object or a static object. In this connection, heretofore, a method for detecting an object has been developed. In this method, a current image is estimated from a past (prior) image by using movement information of the moving vehicle and a distance measuring sensor, and a difference between the estimated image and the current image is determined. However, a sensor for measuring a distance to the object in the image is necessary in order to create the estimated image of the entire image.
As a method that does not use the sensor for measuring the distance, JP-A 2006-268076 (KOKAI) discloses a bird's eye image is created from which only a distance from a camera image to the ground can be measured accurately. An image conversion is performed so that a roadside line on a past bird's eye image coincides with a roadside line on a current bird's eye image. Then, an inconsistent point between the roadside lines is detected as the object. However, in JP-A 2006-268076, the method does not determine whether the roadside line is actually a line on a road surface or not. Moreover, it is premised that the roadside lines correspond to each other between the current and past images, and this method cannot be used in the case where many moving objects exist on the road surface. Furthermore, even in the case where the number of moving objects is small, virtual images are formed at positions where the moving objects existed in the past since each difference is taken in the entire image. This may cause a malfunction, and in addition, a moving object and a static object cannot be identified from each other.
As described above it has been difficult to detect accurately an object without a sensor for measuring a distance.